DOCSLIB.ORG

The Determination of Uneven Pulmonary Blood Flow from the Arterial Oxygen Tension During Nitrogen Washout

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
The Determination of Uneven Pulmonary Blood Flow from the Arterial Oxygen Tension During Nitrogen Washout THE DETERMINATION OF UNEVEN PULMONARY BLOOD FLOW FROM THE ARTERIAL OXYGEN TENSION DURING NITROGEN WASHOUT Theodore N. Finley J Clin Invest. 1961;40(9):1727-1734. https://doi.org/10.1172/JCI104395. Research Article Find the latest version: https://jci.me/104395/pdf THE DETERMINATION OF UNEVEN PULMONARY BLOOD FLOW FROM THE ARTERIAL OXYGEN TENSION DURING NITROGEN WASHOUT By THEODORE N. FINLEY * (From the Cardiovascular Research Institute, University of California Medical School, San Francisco, Calif.) (Submitted for publication January 3, 1961; accepted May 29, 1961) Many tests are available for measuring un- lungs. The test requires the use of a nitrogen evenness of pulmonary ventilation. In recent meter and a flow-through cuvet 02 electrode for years tests of unevenness of pulmonary blood measuring arterial Po2 continuously during the flow have been described, which utilize radio- inhalation of 02. In practice the test takes ap- active krypton (1) in patients with emphysema, proximately 20 minutes and the calculations radioactive oxygen in patients with mitral steno- another 20 minutes. This method is based on sis (2), and radioactive carbon dioxide in normal the principle that the rate of rise of alveolar 02 subjects (3). These studies provide quantita- tension during oxygen inhalation depends on the tive data on the degree of unevenness of pul- distribution of inspired 02 to well and poorly monary blood flow but require expensive and ventilated regions of the lung (in relation to complicated apparatus and are not easily their volume), while the rate of simultaneous adapted to clinical pulmonary function testing. rise of arterial 02 tension depends on the dis- Simpler methods of estimating unevenness of tribution of pulmonary blood flow to these blood flow in relation to ventilation have been regions and the anatomical shunts. The theory, suggested. These are based on the rate of rise method and results of these studies in normal of arterial oxygen saturation (ear oximeter) subjects and in patients with cardiac and pul- during the inhalation of oxygen (4-6), analysis monary disease are presented here. of gas samples obtained from various lobes of the lungs (7), continuous analysis of a single THEORY expiration (8), and the difference between the The lungs can be divided into a well ventilated region nitrogen tension of alveolar gas and urine (9, (which need not be homogeneous) and a poorly ventilated 10). These simpler methods do not provide region (subscripts 1 and 2, respectively). Arterial blood quantitative data on the degree of unevenness of is a mixture of blood that has passed through these regions or through venous-to-arterial shunts. Its oxygen content pulmonary blood flow. (Ca) is related to the blood flows through the capillaries of An ingenious graphical method of determining the various regions (Q1, Q2) and through the shunt (Q8), unevenness of perfusion of the lung in patients and to their respective oxygen contents (Cl, C2 and Cv) as with chronic pulmonary emphysema has been follows: worked out by Briscoe and co-workers (11). Ca QT = C1 Q1 + C2Q2 + CQ9 [1] This method utilizes a nitrogen washout and where Qi + Q2 + Qs = QT, the cardiac output. In this wash-in technique and the arterial saturation and subsequent formulations we omit, from our otherwise (luring air-breathing. Its disadvantage is that conventional (12) symbolization, the subscript c for capil- lary and the chemical subscript 02- other causes of arterial desaturation i.e., shunts It follows from Equation 1 that at any time (t) during and diffusion barriers cause an overestimation the N2 washout: of the degree of unevenness of perfusion. In this laboratory we have devised a test Cat = C (t( ) +C2t which yields quantitative data for the deter- Q1 +Q2 Q1 +Q2 mination of the fractional alveolar ventilation (C. C.,) t -. 0.1. [2] and pulmonary capillary blood flow that go to Ql + Q2 the well and poorly ventilated regions of the Wre assume the following are constant in the later stages of the N2 washout: 1) the magnitude of the various blood * Fellow of the National Tuberculosis Association. Sup- flOwS (QI, Q2, Q., QT) relative to each other; 2) the arteri- ported in part by ITSPHS Grant H-4029. ov5eiious 02) content difference (Ca - Cv). When we then 1 727 1728 THEODORE N. FINLEY consider the difference between the final equilibrium state lated region, because the assumptions that allow the cal- at time f and the changing state at time t, it follows that: culation of PEN2 are not valid in the early portion of the N2 washout. The distribution of pulmonary blood flow is Caf - Cat = (Cf -C1)CIO matched with the distribution of alveolar ventilation when the fractional perfusion equals the fractional ventilation of the poorly ventilated region. + (C2f - C2t) ( QQ Q ) [3] The dilution index. A template was made in which log II/El + (1/n)]hn is plotted against n. This was laid Late in the washout when hemoglobin is fully saturated over the semilogarithmically plotted data and analyzed in all parts of the lung, further changes in 02 content are into linear components (16, 17) (Figure 1). The inter- linearly related to changes in 02 tension (13). Equation 3 section of the curved template with each straight line gives can then be formulated in terms of differences in Po2: a value of n (on the baseline) which is the dilution index. This index, which is related to the turnover rate (k) of Paf - Pat = (Pif - Pit) ( Q + ) Robertson, Siri and Jones (16) is the ratio FRC/VT - VD for each region. The use of the dilution index and its determination by a + (32f - P2f) (. Q Q )E[4] template has proved to be a useful shortcut in the calcula- tion of the functional residual capacity (FRC) and alveolar Any Po2 gradient due to diffusion difficulty becomes in- tidal volumes of the well and poorly ventilated regions. finitesimal at this time when Po2 is high in all alveoli It also provides a simple characterization of the alveolar (13-15). Alveolar and end-capillary oxygen tensions are ventilation of any region. thus identical within a region; i.e., PAI = Pi, PA2 =P2. Mixed expired alveolar versus end-tidal nitrogen concen- If Pco2 is constant within each region, then Po2 is related trations. In our study we measured end-tidal N2 concen- to PN2, provided that the total pressure of all gases is con- stant, as it is, in each region, and hemoglobin is fully satu- rated, as it is, at this time. Then: Paf - Pat = AP1N2 (+.0 ) + AP2N2 (CQ2) = APCN2 [5] where the various values of APN2 are the excess at time t over the final' value at timef. APCN2 is the mean value of this excess in mixed end-capillary blood. This relation holds, regardless of the number of regions. Late in the washout the concentration of nitrogen has become negligible in all but the worst ventilated region. The contributions of N2 from the inspired 02 tank and front the tissues are virtually constant; while they affect the final value they are of no significance in these considera- tions of the changes in PN2. It follows that, late in the washout: VAT APAN2 = VA2* APA2N2 and QT APaN2 = QO2AP2N2, where the subscript T refers to total alveolar ventilation or total cardiac output. Since APA2N2 = AP2N,, these two equations yield the ratio between those fractions of total alveolar ventilation and total perfusion, respectively, which are distributed to the poorly ventilated region: NO. OF BREATHS = (VA2/VAT)/(Q2/QT) APAN2/APCN2 [6] FIG. 1. PERCENTAGE OF N2 CONCENTRATION IN END- At the end of the N2 washout this ratio is constant, since EIXPIRED GAS ON LOGARITHMIC SCALE PLOTTED AGAINST semilogarithmically plotted values of APXN, and APCN2 are NUMBER OF BREATHS FOR THE WELL AND POORLY VENTI- LATED REGIONS OF THE LUNG. The dotted lines found to lie on parallel lines. When (VA2/VAT), APAN2 represent and APCN2 are experimentally determined, Q2/QT can be the N2 washouts of the well and poorly ventilated com- calculated. No attempt has been made to estimate the partments obtained from the N2 end-tidal washout. The distribution of perfusion to compartments in the well venti- dilution index template is superimposed on these graphs, giving an intercept value with the well ventilated region For present purposes we consider N2 washout complete at breath 5 and with the poorly ventilated region at breath when the forced end-expired PN2 is less than 4 mnmi Hg. 20. 1729 DETERNIINATION' OF UTNEVEN PUTLMIONARY BLOOD FLOW\ FIG. 2. RIGHT, CLARK 02 ELECTRODE (A) IN LUCITE JACKET (B) AND LEFT, THE FLOW-THROUGH CUVET (C-D) FOR THE ELECTRODE SHOWING THE HOLES (E) THAT ALLOW CIRCULATION THROUGH TUBES (F AND G) FROM THE WATERBATH AROUND CUVET AND ELECTRODE. The left-hand part fits snugly beneath the right-hand part and the membrane of the Clark electrode is in the flowing blood stream. The fact that these concentrations exceed mixed of the N2 washout on a Severinghaus modification of the tration. in this alveolar and mixed expired concentrations does not affect Clark 02 electrode (19). The Clark electrodes used over the 0 to 95 per cent 02 our determination of the dilution indices nl and n2 (18). study were slightly alinear 21 per cent 02, But this fact does necessitate the use of an additional piece range. This alinearity occurred below in determining the absolute volumes and which affected the accuracy of the Po2 record in the earlier of information deter- ventilations of the various regions. We hav-e used the part of each study but not in the later part used in to determine alveolar *ventilation mining the distribution of perfusion.
Load more

Recommended publications
  • Testing Regimes 3364-136-PF-01 Respiratory Care Approving Officer
    Name of Policy: Testing Regimes Policy Number: 3364-136-PF-01 Department: Respiratory Care Approving Officer: Associate VP Patient Care Services / Chief Nursing Officer Responsible Agent: Director, Respiratory Care Scope: Effective Date: June 1, 2020 The University of Toledo Medical Center Initial Effective Date: July 1, 1979 Respiratory Care Department New policy proposal X Minor/technical revision of existing policy Major revision of existing policy Reaffirmation of existing policy (A) Policy Statement Pulmonary function testing is to be ordered according to these regimes or as individual procedures. All tests may be ordered individually. (B) Purpose of Policy To standardize the ordering procedures for pulmonary function testing. (C) Procedure 1. Pulmonary Function Test I: a. Nitrogen washout test: Determination •Functional Residual Capacity (FRC) • Indirect calculation of Residual Volume (RV) • In conjunction with the Slow Vital Capacity, determination of all lung volumes. b. Carbon Monoxide single breath test: • Determination of diffusing capacity (DLCO-sb) c. Slow Vital Capacity: determination of • Slow Vital Capacity (SVC) • Expiratory Reserve Volume (ERV) • Inspiratory Capacity (IC) d. Flow/Volume Loop: determination of the mechanics of breathing: • Forced Vital Capacity (FVC). • Forced Expiratory Volume in one second (FEV-1) %FEV-1/FVC • Average Forced Expiratory Flow between 25% and 75% of vital capacity (FEF 25-75%) • Maximum Forced Expiratory Flow (FEF-max) • Forced Expiratory Flow at 25%, 50% and 75% of vital capacity (FEF 25%, FEF 50%, FEF 75%) • Forced Inspiratory Vital Capacity (FIVC) • Average Forced Inspiratory Flow between 25% and 75% of FIVC (FIF 25-75%), Forced Inspiratory Flow at 25%, 50% and 75% of FIVC (FIF 25%, FIF 50%, FIF 75%) • FIVC/FVC ratio Policy 3364-136-PF- 01 Testing Regimes Page 2 •FIF 50/FEF 50 ratio e.
    [Show full text]
  • Multiple-Breath Nitrogen Washout Techniques: Including Measurements with Patients on Ventilators
    Eur Respir J 1997; 10: 2174–2185 Copyright ERS Journals Ltd 1997 DOI: 10.1183/09031936.97.10092174 European Respiratory Journal Printed in UK - all rights reserved ISSN 0903 - 1936 ERS/ATS WORKSHOP REPORT SERIES Multiple-breath nitrogen washout techniques: including measurements with patients on ventilators C.J.L. Newth*, P. Enright**, R.L. Johnson+ CONTENTS Definition ....................................................................... 2174 Nitrogen washout test for infants and young children Methods for determining FRC ................................... 2175 FRC measured during spontaneous ventilation ........ 2178 Choice of method Assumptions and limitations of the method ............. 2178 FRC measurement during mechanical ventilation FRC measured by plethysmography (FRCpleth) ......... 2175 Helium (He) dilution ................................................. 2179 FRC measured by helium dilution (FRCHe) ............. 2175 Sulphur hexafluoride (SF6) washout ......................... 2179 FRC measured by nitrogen washout (FRCN2) ........... 2175 Nitrogen (N2) washout ............................................... 2179 Standards for lung volume measurement by gas Procedure for testing .................................................. 2180 dilution/washout techniques ......................................... 2177 Assumptions and limitations ..................................... 2180 Nitrogen washout test for adults and older, Equipment and technical procedures ......................... 2181 Normal values: spontaneous breathing
    [Show full text]
  • Calculation of Lung Volume in Newborn Infants by Means of a Computer-Assisted Nitrogen Washout Method
    SJOQVIST ET AL. 003 1-3998/84/18 1 1-1 160$02.00/0 PEDIATRIC RESEARCH Vol. 18, No. 1 1, 1984 Copyright O 1984 International Pediatric Research Foundation, Inc. Printed in U.S.A. Calculation of Lung Volume in Newborn Infants by Means of a Computer-assisted Nitrogen Washout Method BENGT ARNE SJOQVIST, KENNETH SANDBERG, OLA HJALMARSON, AND TORSTEN OLSSON Research Laboratory of Medical Electronics, Chalmers University of Technology [B.A.S., T.O.] and Department of Pediatrics I, University of Gateborg [K.S., O.H.], Gateborg, Sweden ABSTRACT. A clinically adapted method for the calcula- uring F~c.Despite its central importance, measurements of tion of the functional residual capacity in newborn infants FRC are seldom used clinically in neonatal medicine, because of has been developed. The method is based on a multiple the lack of suitable methods. breath nitrogen washout test, during which the ventilatory Therefore, in order to facilitate such measurements, we have air flow and the nitrogen concentration signals are sampled developed a clinically adapted computer-assisted plethysmo- by a minicomputer, which also performs the calculations. graphic nitrogen washout method for the calculation of FRC in The ventilatory air flow is measured by a pneumotachom- newborn infants, which reduces the problems connected with eter connected to a face-out volume displacement body ordinary washout methods (3, 8, 15). It also enables further plethysmograph, and the nitrogen concentration by a nitro- analysis of the collected washout data, for instance nitrogen gen analyzer. The functional residual capacity volume is elimination pattern ("distribution of ventilationn) analysis. The calculated from the sampled signals by adding the expired method has been tested on a group of healthy newborn infants nitrogen volumes during each expiration, and finally divid- and on a mechanical lung model.
    [Show full text]
  • Effects of Continuous Positive Airway Pressure on Pulmonary Function and Blood Gases of Infants with Respiratory Distress Syndrome
    Pediat. Res. 12: 771-774 (1978) Continuous positive airway pressure pulmonary function functional residual capacity respiratory distress syndrome hyaline membrane disease Effects of Continuous Positive Airway Pressure on Pulmonary Function and Blood Gases of Infants with Respiratory Distress Syndrome C. PETER RICHARDS ON'^" AND A. L. JUNG Division of Neonatology, Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, Utah, USA Summary the infants were 33.7 -+ 0.4 wk and 2013 + 93 g. Some infants were studied several times during the course of their disease so Nitrogen washout measurements and blood-gas analyses were that 52 sets of data were gathered at infant postnatal ages ranging made on 32 newborn infants with severe RDS at continuous from 4 to 152 h (mean 38 h). Four of the infants required positive airway pressures (CPAP) of 5, 10, and 15 cm H2O. mechanical ventilation due to the inability to maintain Paon of 60 Increases in airway pressure resulted in significant increases in mm Hg with airway pressure greater than 15 cm HzO and FiOz of Pa02 and functional residual capacity (FRC). It also produced 1.0. Three of these four infants died of intraventricular hemor- significant decreases in alveolar turnover rates of the "fast" and rhages. A fourth infant died of necrotizing enterocolitis. All four "slow" alveolar spaces of a two-space lung model. Changes in infants that died also had pneumothoraces, and were the only CPAP did not significantly affect the distribution of ventilation. infants with pneumothoraces. The changes in PaO2. due to changes in CPAP, did not correlate well with changes in &/wt nor wi& changes in'alveolar turnover EQUIPMENT rates.
    [Show full text]
  • Infant/Toddler Pulmonary Function Tests (2008)
    AARC Clinical Practice Guideline Infant/Toddler Pulmonary Function Tests—2008 Revision & Update ITPFT 1.0 PROCEDURE: 2.4.3 Tidal breathing measures: RR; time Infant/toddler pulmonary function tests (ITPFTs) to reach peak tidal expiratory flow (tPTEF); 41, total expiratory time (tE); ratio of tPTEF/tE ITPFT 2.0 DESCRIPTION/DEFINITION: 42 2.4.4 Partial expiratory flow-volume 2.1 Infant/toddler pulmonary function tests curves: maximal flow at functional residual measure a variety of pulmonary variables in capacity (VmaxFRC) 49, 68 subjects who are generally too young to per- 2.4.5 Raised volume rapid thoracoabdomi- form, comprehend, or comply with necessary nal compression technique: forced vital ca- instructions for conventional pulmonary diag- pacity (FVC); forced expired volume at 0.5 nostic procedures and 0.75 seconds respectively (FEV0.5, 2.2 Subjects are typically tested under con- FEV0.75); forced expiratory flow at 25%, scious sedation or while sleeping and are spon- 50%, 75% and between 25% and 75% of taneously breathing. ITPFTs have also been FVC (FEF25, FEF50, FEF75, FEF25-75) performed in subjects who are mechanically 68, 73 ventilated. 2.4.6 Whole body plethysmography: 2.3 ITPFTs may include measurements of: plethysmographic functional residual ca- 2.3.1 Passive respiratory mechanics, 1-35 pacity (FRCpleth); airway resistance 2.3.2 Dynamic respiratory mechanics, 32, 33, (Raw) 97, 101 35-39 2.4.7 Gas dilution techniques: helium dilu- 2.3.3 Tidal breathing measurements, 1, 35, 40 -42 tion (FRCHe), nitrogen washout (FRCN2), 2.3.4
    [Show full text]
  • Patient Testing – Functional Residual Capacity Testing on Ultima ______Audience All Personnel in the Pulmonary Function Clinic
    University of Texas Medical Branch Effective Date: Apr 02 Pulmonary Function Clinic Revised Date: May 14 Policy 03-09 Functional Residual Capacity Review Date: May 14 Patient Testing – Functional Residual Capacity Testing on Ultima _____________________________________________________________________________ Audience All personnel in the Pulmonary Function Clinic. _____________________________________________________________________________ Purpose To describe the procedure for performing Functional Residual Capacity (FRC) on the Ultima in the Pulmonary Function Clinic. FRC is the volume of gas remaining in the lungs at the end of a quiet breath. Residual volume (RV) cannot be exhaled; it is the volume remaining in the alveoli after the airways have closed. FRC is measured and the RV calculated by subtracting expiratory reserve volume (ERV) obtained from simple spirometry. _____________________________________________________________________________ Instructing the Patient Standard testing procedures begin with instructing the patient and demonstrating proper technique. The greatest potential source for error is the failure of the patient to perform the test properly. If the patient is relaxed, the end-expiratory volume will represent true resting end-tidal volume (FRC). _____________________________________________________________________________ Prior to Testing The following steps should be done prior to testing the patient: Be sure the system has been warmed up and that the daily complete pneumotach calibration has been performed. Select the FRC N2 tab. They system begins the pre-test calibration. Attach the pneumotach clip to the Profiler cal port. At this point please perform a gas calibration before testing a patient. The system samples room air. If the room air N2 levels is not within the systems allowable range (79.6% +/-2%), flush the system with room air using a calibration syringe.
    [Show full text]
  • Patient Testing – Diffusion Capacity Profiler & Elite
    University of Texas Medical Branch Effective Date: Apr 02 Pulmonary Function Clinic Revised Date: Oct 05 Policy 03-07 Diffusion Capacity Review Date: May 14 Patient Testing – Diffusion Capacity Profiler & Elite Plethysmograph _____________________________________________________________________________ Audience All personnel in the Pulmonary Function Clinic. _____________________________________________________________________________ Purpose To describe the procedure for performing Diffusion Capacity (DLCO) on the Profiler and Elite Plethysmograph in the Pulmonary Function Clinic. Diffusion Capacity is measured by using small volumes of carbon monoxide to assess the gas exchange ability of the lungs across the alveolocapillary membrane. ______________________________________________________________________________ Cautions DLCO Testing is performed using the pre-vent pneumotach and mouthpiece connected to the pneumotach umbilical. The pneumotach must also be connected to the patient circuit in the arm of the Profiler or Elite. Note: If both diffusion and nitrogen washout tests are to be conducted, the diffusion test should be performed first. Inhaling 100% oxygen during a nitrogen washout test may saturate the hemoglobin and decrease the patient’s diffusion capacity values. ______________________________________________________________________________ Instructing the Patient Standard testing procedures begin with instructing the patient and demonstrating proper technique. The greatest potential source for error is the failure of the patient to perform the test properly. _____________________________________________________________________________ Prior to Testing The following should be performed prior to testing: Be sure you have warmed up the system and performed the daily complete pneumotach calibration. Before testing the Helium (He) gas must be on for twelve minutes. Warm-up time is displayed on the associated timer at the top of the screen. Tip: Deterioration of the gas chromatograph column is affected by the volume of helium passing through it.
    [Show full text]
  • PFT Interpretation
    PFT Interpretation Presented by: Shazhad Manawar, MD Medical Director Respiratory Care & Pulmonary Rehab McLaren Bay Region Introduction History or symptoms suggestive of lung disease. Risk factors for lung disease are present. Pulmonary Function Tests Spirometry Spirometry before and after bronchodilator Lung volumes Diffusing capacity for carbon monoxide Maximal respiratory pressures Flow volume loops Spirometry Volume of air exhaled at specific time points during forceful and complete exhalation. Total exhaled volume, know as the FVC (forced vital capacity). Volume exhaled in the first second, know as the forced expiratory volume in one second (FEV1) Spirometry - continued Ratio (FEV1/FVC) are the most important variables Minimal risk Key diagnostic test Asthma Chronic Obstructive Pulmonary Disease (COPD) Chronic cough Spirometry - continued Monitor a broad spectrum of respiratory diseases. Asthma COPD Interstitial Lung Disease Neuromuscular diseases affecting respiratory muscles Spirometry - continued Slow vital capacity (SVC) Useful measurement when FVC is reduced and airway obstruction is present Post-bronchodilator Determine the degree of reversibility Administration of albuterol Technique is important Increase in the FEV1 of more than 12% or greater than 0.2 L suggests acute bronchodilator responsiveness. Subjective improvements Post-bronchodilator - continued Thus, the lack of an acute bronchodilator response on spirometry should not preclude a one to eight week therapeutic trial of bronchodilators
    [Show full text]
  • Ventilation Inhomogeneity in Infants with Recurrent Wheezing
    Paediatric lung disease ORIGINAL ARTICLE Thorax: first published as 10.1136/thoraxjnl-2017-211351 on 15 June 2018. Downloaded from Ventilation inhomogeneity in infants with recurrent wheezing Zihang Lu,1,2 Rachel E Foong,1,3 Krzysztof Kowalik,1 Theo J Moraes,1 Ayanna Boyce,1 Aimee Dubeau,1 Susan Balkovec,1 Per Magnus Gustafsson,4 Allan B Becker,5 Piush J Mandhane,6 Stuart E Turvey,7 Wendy Lou,2 Felix Ratjen,1 Malcolm Sears,8 Padmaja Subbarao1 ► Additional material is ABSTRact published online only. To view Background The care of infants with recurrent Key messages please visit the journal online (http:// dx. doi. org/ 10. 1136/ wheezing relies largely on clinical assessment. The thoraxjnl- 2017- 211351). lung clearance index (LCI), a measure of ventilation What is the key question? inhomogeneity, is a sensitive marker of early airway ► Does infant lung function as reported in lung 1Division of Respiratory disease in children with cystic fibrosis, but its utility has clearance index (LCI) measured from multiple Medicine and Translational not been explored in infants with recurrent wheezing. breath washout improve the phenotyping of Medicine, Department of infants who have a history of severe wheezing Pediatrics & Physiology, Hospital Objective To assess ventilation inhomogeneity using for Sick Children & University LCI among infants with a history of recurrent wheezing disorders? of Toronto, Toronto, Ontario, compared with healthy controls. What is the bottom line? Canada Methods This is a case–control study, including 2Dalla Lana School of Public ► LCI is elevated in a clinical cohort of 37 infants with recurrent wheezing recruited from Health, University of Toronto, infants referred for recurrent wheezing outpatient clinics, and 113 healthy infants from a Toronto, Ontario, Canada disorders suggesting persistent ventilation 3School of Physiotherapy longitudinal birth cohort, the Canadian Healthy Infant inhomogeneity.
    [Show full text]
  • ATS/NHLBI Consensus Document 12 Nov 03 1
    ATS/NHLBI Consensus Document 12 Nov 03 1 CONSENSUS STATEMENT ON MEASUREMENTS OF LUNG VOLUMES IN HUMANS JL Clausen and JS Wanger for the Workshop participants. Developed from workshops sponsored by the American Thoracic Society and the National Heart, Lung, and Blood Institute (conference grant #R13 HL48384-01). Workshop participants included: Eduardo Bancalari, M.D., University of Miami; Miami Florida Robert A. Brown, M.D., Massachusetts General Hospital, Boston, Massachusetts Jack L. Clausen, M.D. University of California, San Diego (Co-Chairman) Allan L. Coates, M.D., Hospital for Sick Children, Toronto, Canada (Co-Chairman) Robert O. Crapo, M.D. LDS Hospital, Salt Lake City, Utah Paul Enright, M.D. U of Arizona, Tucson, Arizona Claude Gaultier, M.D., PhD, Hôpital Robert Debré, Paris, France John Hankinson, Ph.D. NIOSH, Morgantown, WV Robert L. Johnson, Jr. M.D. U of Texas, Dallas Texas David Leith, M.D., Kansas State University, Manhattan Kansas Christopher J.L. Newth, M.D. Children's Hospital, Los Angeles, California Rene Peslin, M.D.Inserm, Vandoeuvre Les Nancy France Philip H. Quanjer, M.D. Leiden University, Leiden, The Netherlands (Co-chairman) Daniel Rodenstein, M.D. Cliniques St. Luc, Brussels, Belgium Janet Stocks, Ph.D. Institute of Child Health, London England Jean Claude Yernault, M.D. Hospital Erasme, Brussels, Belgium ATS staff: Graham M. Nelan, New York, NY NHLBI staff: James P. Kiley, Ph.D., Bethesda, Maryland ATS/NHLBI Consensus Document 12 Nov 03 2 MEASUREMENTS OF LUNG VOLUMES IN HUMANS TABLE of CONTENTS: 1. Introduction 2. Terminology 3. Effects of nutrition, growth hormone, training, and altitude on lung volumes 3.1 Effects of nutrition 3.2 Effects of growth hormone 3.3 Effects of training 3.4 Effects of altitude 4.
    [Show full text]
  • Oxygen Does Not Hasten Resolution of Symptomatic Spontaneous Pneumothorax in Neonates
    Journal of Perinatology (2014) 34, 528–531 © 2014 Nature America, Inc. All rights reserved 0743-8346/14 www.nature.com/jp ORIGINAL ARTICLE Administration of 100% oxygen does not hasten resolution of symptomatic spontaneous pneumothorax in neonates SD Clark1,2, F Saker1,2, MT Schneeberger1,2, E Park2,3, DW Sutton2,4 and Y Littner1,2 OBJECTIVE: To compare the effectiveness of 100% oxygen therapy vs oxygen treatment with targeted pulse oximetry in the management of symptomatic small to moderate spontaneous pneumothorax (SP). In total, 100% oxygen treatment for SP has been a common practice in neonatology, albeit there is little evidence to validate its efficacy. STUDY DESIGN: A retrospective chart review of 83 neonatal records with the diagnosis of pneumothorax was conducted. Infants o35 weeks gestation, those with large pneumothoraces requiring chest tube drainage and/or ventilatory support were excluded. Data gathered included demographics, vital signs, treatment information and clinical indicators of resolution of symptoms. RESULT: In total, 45 neonates with SP were included in the study. Groups were similar for gestational age, birth weight, Apgar scores, gravidity, parity, gender, race, pneumothorax size and location. Patients in the 100% oxygen therapy group received a significantly longer oxygen treatment (21.3 vs 8 h, Po0.001), required longer intravenous fluid treatment (48.6 ± 29.9 vs 31.3 ± 18.8 h, P = 0.03) and were delayed in reaching full feeds (44.1 ± 25.7 vs 29.5 ± 18.8 h, P = 0.03) compared with the oxygen-targeted treatment group. Time to first oral feeding, time to resolution of tachypnea and length of stay were similar in both groups.
    [Show full text]
  • Nitrogen Multiple Breath Washout Test for Infants with Cystic Fibrosis
    AGORA | RESEARCH LETTER Nitrogen multiple breath washout test for infants with cystic fibrosis To the Editor: Multiple breath washout test (MBW) with lung clearance index (LCI) as a main outcome parameter has proven to be a valuable research tool in patients with cystic fibrosis (CF) [1, 2]. Moreover, there is growing evidence of its relevance in routine clinical practice [3]. Nevertheless, some technical limitations remain that hamper its widespread use. While most of the MBW data in infants have been acquired via sulfur – – hexafluoride washout (SF6 MBW), the nitrogen variant (N2 MBW) is recommended by the European Cystic Fibrosis Society Clinical Trial Network (ECFS–CTN) for older children. However, this – methodological discrepancy may limit long-term follow-up of cystic fibrosis patients because N2 and – – SF6 MBW cannot be used interchangeably. In infants, the N2 MBW has not been fully investigated to date. – We report our data regarding safety, feasibility and repeatability of N2 MBW in cystic fibrosis infants. Between January 2015 and January 2017, we performed lung function testing in 35 infants aged 6.7– 25.2 months (median 14.7) with classical form of cystic fibrosis. Testing was performed in patients without any signs of acute respiratory infection for at least 14 days. Quiet sleep was induced by administering − chloral hydrate 80–100 mg·kg 1 per rectum. The patients were placed in a supine position with their head and neck in a neutral position, and a Rendell–Baker face mask Nr. 1 or 2 (selected to keep the instrument −1 – dead space under 2 mL·kg ) was tightly sealed around the mouth and nose.
    [Show full text]